This attractive puzzle designed by Martin Watson of UK has the digits 1 thru 9 made from 2 different hardwoods.  Your objective is to fit them into the box.  Once in the box they form the attractive lattice pattern seen in the photo.

Its quite a challenging puzzle, yet addicting to even folks who may not normally tackle a challenging one as you seem to get close in a short period of time.  But, don't look to solve this one quickly!  An hour would be a fabulous solution time..